Mixed electronic-ionic conducting La0.6Sr0.4Co0.2Fe0.8O3 ceramics were prepared by a citrate method and a conventional solid state method, respectively. The chemical state of oxygen on the surfaces of the ceramics made by the two different methods was characterized by X-ray photoelectron spectroscopy (XPS). It was detected that there are five different kinds of oxygen on the ceramic surfaces, including lattice oxygen (OL), chemisorbed oxygen (Oc) in the forms of, O-2, O-1, and O-1, and oxygen in hydroxyl environment (OH). The concentrations of OC +OH relative to total detected oxygen attain 67.11% and 64.80% for the specimens made by the citrate method and the solid state method, respectively. Compared with the specimen made by the solid state method, the specimen made by the citrate method generally exhibits relative larger electronic conductivity and ionic conductivity at an identical measuring temperature. An essential relation between the chemical states of oxygen on the surfaces and the electrical nature of the ceramics was confirmed. It was considered that the mixed electronic-ionic conducting properties are responsible for the complex chemical states of oxygen on the ceramic surfaces.